1. Field of the Invention
The present invention relates generally to solar energy recovery and utilization and, more particularly, it relates to a novel foundation and building structure in which, for a relatively modest increase in construction cost, substantially all heating/cooling requirements can be supplied by solar energy, at least in most temperate zone climates.
Solar energy collectors proposed and/or built to date to meet household or industrial heating requirements generally use water or other liquids as the heat transfer medium, the water circulating through specially-designed, roof-mounted glass-covered collector panels, with the heat being stored in large, insulated tanks at or below ground level. Coils within the tank circulate a second heat transfer fluid for interior heating purposes.
While mass production of a standarized collector panel of the type described may ultimately make the capital cost of such systems reasonable, this appears to be many years away.
Other than noting the obvious expedient of providing good insulation for energy conservation, such systems are proposed for essentially conventional structures. Further, insofar as is known such systems are proposed only to meet heating requirements, and ignore the available energy potential for meeting cooling requirements as well. In many sections of the United States, energy expended on cooling exceeds that used for heating and it is these same locations, obviously enough, where available solar energy is greatest.
Solar powered electrical generators of the semiconductor type are now reasonably efficient, but their cost is at present prohibitive.
2. Prior Art
Understanding of the present invention will be facilitated by brief consideration of some of the prior art systems proposed heretofore, including their advantages and disadvantages.
U.S. Pat. No. 2,342,211 of Newton discloses using a heating coil filled with a liquid and insulated from a sloping roof to collect or radiate heat. The liquid (and energy therein) is stored in the attic and transmitted to the air inside the building by radiators of a conventional nature.
U.S. Pat. No. 2,484,127 of Stelzer discloses using a plate of glass over a sloping roof to collect or radiate heat which is recirculated via air ducts to refractory bricks or tile arranged in a vertically inclined mass to effect thermal convection as an aid to recirculation.
U.S. Pat. No. 2,650,565 of Lof collects solar energy in a glass covered heat trap comprising partially opaque glass plates and moves this energy by heating air to a heat storage bin containing a loose or spaced solid such as sand, gravel or stacked brick, or a fluid such as tar, oil, water or the like.
U.S. Pat. No. 3,412,728 of Thomason utilizes a solar heat collector having a sloping metal roof spaced from a transparent cover thereover, with air circulating upwardly between the roof and cover to carry heat to the side of the building and downward to heat storage means comprising building blocks on which are supported a gravel layer.
More recently, Falbel, in U.S. Pat. No. 3,841,302, proposes a building attic having a moveable wall and interior reflective surfaces so that solar energy is concentrated on a relatively small collector, which can be of the heat transfer fluid or solar-cell type.
These systems must all be considered labor and capital-intensive in the first (i.e. construction) instance. Systems employing transparent surfaces and/or liquid piping must also be considered to have significant added upkeep costs, due to normal weathering, material failure etc. Perhaps even more important, the prior art systems depend either on substantial temperature differentials (sometimes referred to as .DELTA.T) for heat transfer over a limited surface area, or concentration of solar energy values prior to performance of any heating function. As will become clear from the description of the present invention, both economy and efficiency are realized by maximizing surface areas for both collection and storage of heat, while minimizing required .DELTA.T.